Theory of Surface Electronic Structure

This chapter describes a newly developed, highly accurate, and unified method for calculating surfaces, the full-potential linearized augmented plane wave (FLAPW) method. This is a unified method in that it can easily treat not only simple metals and semiconductors but also transition-metal surfaces. It is also unified in the sense that it is capable of treating molecular absorption on surfaces and also the extreme limit of the isolated molecule and the clean surface. In this approach, which represents a major advance in that the local density equations are solved without any shape approximations to the electronic potential or electronic charge density, a new technique for solving Poisson's equation for a general charge density and potential has been implemented. The chapter discusses the general theoretical framework for the FLAPW calculations: the thin-slab structural model for surfaces and the local-(spin)-density-functional approximation and the limitations of each of these. It presents the FLAPW methodology a selection of applications with examples that illustrate its applicability to a variety of surface and interface phenomena.